I was having a phone call with one of my friends.
Friend: How about we hang out together this Saturday?
I: Sunday is better, because I have a meeting in Saturday morning which will probably last for a long time.
Is my response clear and natural? I meant if the meeting will be finished in one hour, we can hang out on Saturday. But the meeting is probably longer than that and it's inappropriate to have my friend wait me for that long.
Are there any other expressions more natural I could use in the context?